Divalent copper and zinc complex based on a new 4,4′-bis-[(dicarboxymethyl)aminomethyl]biphenyl and N-donor ligands: Syntheses, structures and photoluminescence

Abstract

Seven new coordination compounds, namely, [Cu2(L)(H2O)4]·4H2O (1), [Cu4(L)2(phen)4]·15H2O (2), [Cu2(L)(Him)4]·4H2O (3), [Cu4(L)2(pbib)2(H2O)4]·8H2O (4), [Zn2(L)(pbib)2]·8H2O (5), [Zn2(L)(biim-4)2]·5H2O (6) and [Zn2(L)(biim-4)]·3H2O (7), where biim-4=1,1′-(1,4-butanediyl)bis(imidazole), pbib=1,4-bis(imidazol-1-ylmethyl)benzene, phen=1,10-phenanthroline, Him=imidazole and H4L=4,4′-bis-[(dicarboxymethyl)aminomethyl]biphenyl, have been synthesized by Cu(II) and Zn(II) salts with L anions and N-donor ligands. These compounds were characterized by single-crystal X-ray diffraction analyses and further identified by infrared spectra (IR), elemental analyses, powder X-ray diffraction (PXRD) analyses and thermogravimetric analyses (TG). Compounds 1–3 show zero-dimensional (0D) structures. In compounds 1 and 2, the discrete structures are further linked by intermolecular hydrogen-bonding and π–π interactions to form a two-dimensional (2D) supramolecular layer, respectively. Moreover, in compound 3, the discrete structure is further extended by intermolecular hydrogen-bonding interactions to yield a 3D supramolecular architecture. Compound 4 displays a tetranuclear structure, which is further connected by intermolecular hydrogen-bonding interactions to form a 3D supramolecular structure. Compound 5 shows a 3D 5-fold interpenetrating diamond framework. Compound 6 reveals a 2D 63-hcb network. Compound 7 shows a 3D 6-connected net with the (411·64) topology. In addition, the luminescent properties of 5–7 have also been investigated in details.